Thread controller for sewing machines



June 21, 1932. F F ZElER ET AL 1,864,392

THREAD CONTROLLER FOR SEWING MACHINES Filed April'l5, 1930 3 Sheets-Sheet. l

sme l W008 7km vhf w June 21, 1932. F. F. ZEIER E+ AL 1,864,392

THREAD CONTROLLER FOR SEWING MACHINES Filed April 15. 1930 5 Sheets-Sheet 2.

June 21,1932. ZE R ET AL 1,864,392

THREAD CONTROLLER FOR SEWING MACHINES Filed April 15, 1930 3 Sheets-Sheet 3 mllllln 3 i :q F 31 20 IL. 31 .26

Ill 1 m IIIIIIILIIIIIIIIIIIH u-nmn unmmumu 2 I I llllllllllllllll!" Patented June 21, 1932 UNITED STATES PATENT orrics FREDERICK 'ZEIEB. AND CHARLES E. RUBEL, OF CHICAGO, ELLINQIS, ASSIGNORS TO UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS THREAD CONTROLLER FOR SEWING MACHINES Application filed April 15,

rotation of the thread controlling element.

A further objectof the invention is to provide a thread controlling mechanism of the above type wherein the thread releasing devices are fixed to andtravel with the thread controlling element.

A further object of the invention is to provide -a thread controlling mechanism of the above type wherein the thread controlling element is provided with a second portion which gradually takes up the thread and gradually gives up the thread during each cycle of rotation of the thread controlling element.

In the drawings which show by way of ilf lustration one embodiment of the invention;

Figure 1 is a View partly in plan and partly in section of a portion of a machine embodying the improvements Fig. 2 is a view showing a needle and looper such as may be used in conjunction with the thread controlling mechanism; I

Fig. '3 is a sectional view through the thread controlling mechanism showingin full lines the position of the thread controlling mechanism where the thread is about to be stripped from the portionot the thread controlling element which has taken up the threadysaid figure inbroken lines showing the position of the thread controlling ele- 1930. Serial at. 444,465.

ment when it first engages the thread extending between the thread guides;

Fig. 4 is a view similar to Fig. 3 but showing the thread controller as having moved through a distance sufiicient to strip the threads from the thread controlling member; the section in this view being at one side of the stripper member instead of through the stripper member;

Fig. '5 is a'view similar to Fig. 2 but showing the looper at the rear end of its stroke;

Fig. 6 is a view similar to Fig. 4, but showing the thread controller as havingturned to a position where the thread is about to be taken up by the second thread controller portion on the thread controlling element, and

Fig. 7 is a view showing this second thread engaging portion as having taken up the maximum amount of thread and about to give up the thread.

Fig. 8 is a sectional view through the actuating shaft and inside of the end disk of the thread cont-rolling member.

Fig. 9 is a plan view of the thread controlling member.

Fig. 10 is a side face view of the thread controlling member also'showing the strippers.

I Fig. 11 isa perspective view of the strippers and the supporting plate therefor.

The invention is directed to a thread c0ntrolling mechanism for sewing machines, and w more particularly to a thread controlling mechanism wherein the thread or threads are directed into engagement with a rotating thread controlling element in a direction at right angles to the axis of rotation of said element. In the application filed by Norman V. Christensen, Charles F. Rubel and Frederick 'F."Zeier August 2, 1928, Serial No. 297,059, there is shown,described and claimed a thread controllingmechanism of the above character on which the present invention is an improvement. The thread controlling mechanism of the present invention is particularly adapted to the control ota looper thread, and would possibly be best understood by a detailed description in connection with the operation of a threaded looper.

It is well known that with a threaded looper it is very important to take up the looper thread as the looper begins its retract ing movement so that the thread extending from the eye of the looper to the previous stitch will be drawn taut at the time when the needle passes into the thread triangle. The looper is preferably of an oscillating type, and is given an accelerating and retarding movement, and it is very important that the thread shall be given up to the looper gradually and in proportion to its rate of travel so that the thread between the eye of the looper and the previous stitch will be held substantially taut until the point of the needle has passed beneath the looper thread after which the looper is quickly given slack thread so that it may move to the rear end of its stroke leaving its loop about the needle.

It is also essential in this type of looper to take up the thread as the looper moves forward so as to )revent the thread from buckling in front 0 "the looper eye, and also to give up the thread to the looper as it moves for- Ward into the needle thread loop.

The thread controller of the present invention is provided with means which gradually begins to take up the thread as soon as the looper starts its retracting movement. This thread controlling element continues to gradually and increasingly draw on the thread until the maximum thread pulling effort is produced, and at this time the needle point is well below the looper thread and into the looper thread triangle. The thread controlling element is provided with means which then quickly strips the thread from the takeup shoulder on the thread controlling element so that the thread is substantially slack, thus permitting free movement of the looper to the rear end of its stroke. The thread controlling element is also provided with a second thread engaging portion which engages the looper thread and takes up said looper thread with a fixed-definite engagement therewith until the point of the looper has entered well into the needle thread loop after which the thread is gradually given up as the looper moves on forward to the end of its stroke.

Referring more in detail to the drawings the invention is shown for the sake of illustration as applied to a machine having a sup. porting bracket 1 carrying an upper housing 2 in which is mounted an actuating shaft '3. Fixed to this actuating shaft 3 is a thread controlling mechanism which includes a thread controlling element 4 rotating with its actuating shaft. The machine as shown in Figure. 3 is provided with three threads a,

, Z) and 0. Each thread passes through a tension 5, and thence through a thread guide 6 in an arm 7 which is fixed to a bracket 8 attached to the machine by screws 9, 9. The arm 7 is secured to this bracket by screws 10, 10 passing through a slot 11 in the shank carrying the arm, and this permits the guides to be adjusted toward and away from the thread controlling element. At the opposite side of the thread controlling element there are thread guides 12, one for each thread. These thread guides 12 are formed in an arm 13 which as shown is attached to and a part of the bracket 8.

The machine is provided with a plurality of needles one of which is shown at 14 in Figs. 2 and 5. Cooperating with each needle is a looper 15. This looper 15 is provided with a thread eye 16,.and with a point 17 which enters the needle thread loop. The looper is mounted on a carrier which in turn is mounted on a shaft 18. There are three needles and three loopers where three threads such as shown in the drawings are controlled, and each looper cooperates with its respective needle independently of the other loopers. The three threads are'independently controlled by this single thread controlling element 4:. The rotating thread controlling element is provided with two spaced disks 19, 19, and the element which engages the threads is located between these disks. The disk and the thread controlling element i are secured together by suitable bolts 20, 20. The thread controlling element is held in a fixed position on the shaft by a set screw 21 passing through a sleeve 22 attached to one of the disks 19. The thread controlling element is provided with a thread engaging portion 23. This thread engaging portion 23 is curved from the point 24 to the point 25 eccentrically of the center :0 of the actuating shaft. The thread controlling element turns in the direction of the arrow as shown in the drawings. The thread controlling element in advance of the point 25 is provided with f-shaped thread guiding grooves 26. Said thread controlling element is provided adjacent the point 24 with grooves or slots 27, 28 and 29. These slots extend into the thread controlling element to a depth indicated by the line ale. The curved face of the thread engaging portion 28'extends all the way to the point 24:, as indicated in the figures in the drawings, thus producing a thread engaging face 23 which lies along side of the slots 27, 28'and 29. There is a thread engaging face 23 associated with each groove. The threads passing between the thread guides are directed in spaced relation into the path of rotation of this engagingportion 23, and a thread engaging portion 28 contacts with each thread. These threads between the thread guides are brought into engagement -with the thread controlling element in a direction at right angles to the axis of rotation of the thread controlling element, that is each thread lies in a plane at right angles to the axis of rotation of the threadcontrolling element, and each thread will lie in a different plane so that the thread controlling element operates independently upon each Inasmuch as the thread extends thread. across the thread controlling element in the direction of its rotation there is no tendency of the thread controlling element to crowd one thread toward the other. As the thread controlling element rotates the thread guiding grooves 26 engaging the respective threads will center or place the same so that they will be properly engaged by the thread engaging portion 23 of the thread controlling element, and finally engage the portions 23 thereof.

In Figure 3 of the drawings the thread controlling element is shown in broken lines as engaging and positioning the threads through the aid of these guiding grooves 26 so that they will be properly directed onto the .nread engaging portion 23. hen the looper is at the forward end of its stroke the looper thread is substantially taut, and

the looper starts on its retracting movement the thread controlling element begins to take up on this looper thread. When the parts are in position shown in broken lines in Fig. 3. the looper isjust beginning its retracting motion. The thread engaging portion 23 of the thread controlling element first engages the thread at the point 25, and gradually the thread is laid into engagement with this thread engaging portion 23 until the point 2% is reached. It is apparent from the drawings that the point is a shorter radial. distance from the center of the actuating; shaft than the point 24. The face of the thread engaging member between these points is gradually curved, and will gradually increase the taking up pull on the loopthread. As the looper starts on its retract ng motion inasmuch as it is oscillating its speed gradually increases and the curved face of the thread controlling member 23 is o shaped as to hold the thread constantly under control providing a substantially taut thread between the eye of the looper and the previous stitch during this first part of the retracting i'noveinent of the looper. hen the needle point has passed well by the loopor thread, and thus well into the looper thread triangle it is desirable to release the looper thread at once and give ample slack to the looper thread so that the looper may cmtinue its backward movement while the looper thread loop is held by the needle.

Associating with each thread engaging portion 23* is a stripper device. These stripper devices as shown in the drawings are p fer-ably formed of one integral piece con-- ing of a shank portion 30, and stripper fingers 31. 31, 31. There is a stripper r for each thread engaging face 23. These gaging portion is indicated at 36.

stripper fingers are all of substantially the same width as the portions 23 and the grooves or recesses in which thethread is stripped extend along side of these fingers. The thread controlling element is preferably provided with a recess 32. The shank of the plate carrying the stripper fingers 31 is inserted in this recess. A clamping bolt 33 extends through a slot 34 the shank carrying these figures, and when this screw is turned in it will fixedly clamp the stripper lingers in a set adjusted position relative to the thread controlling element. Each stripper finger has an inclined face 31. These inclined faces project radially beyond the thread engaging portions 23, and when the thread is brought into engagement with these inclined faces of the stripper fingers each thread will be crowded laterally on its respective thread engaging portion 23- until it is stripped off into the groove or recess alon side of the same. It will tlnis be seen that the thread controlling element when it engages the thread on the first backward motion of the looper will gradually take up the thread, holding it taut until the proper tirne when the thread will be stripped from the thread engaging portion and slack given to the looper thread.

in Figure 3 of the drawings in full lines the thread control er is shown just as it is reaching the point where the :ead to be stripped from the thread engaging portions 23, and in Figure 4 the thread controller is shown as it is turned a slight distance in its cycle of movement that the threads have been stripped from their respective thread engaging portions 23 It will be noted that when the thread is stripped. from the thread. engaging portions 23 it is still held in engagement with the shoulder and this shoulder as it rotates will control and gradually give up thread to the looper. The looper, therefore. as soon as the needle p int is well into the looper thread triangle is given ample slack but the slack is still controlled until the looper has reached the rear end of its stroke.

In Figure 6 of the drawings the thread controller'is shown as having given up most of'its slack, and the looper has practically reached the rear end of its stroke, as indicated in Fig. 5. The thread controller is provided with a second thread engaging portion for taking up and giving up slack in the looper thread. This second thread on The thread controller from the point 37 to the point (Z is substantially fiat and it is the porthrcad between the thread guides, and begins totake up the slack in the thread. This takes place as the looper starts on its'forward movement and it will draw the thread back through the eye of the looper and then tion at the point 37 which engages the looper 5 stanti ally fiat.

prevent the thread from buckling in front of the point of the looper. When the thread controller has reached the position shown in Fig. 7 the looper point has entered well into the needle thread loop, and from this point on its rotation the thread controller, will again give up slack. The thread controller from the point 37 to the point 88 is likewise sublhe two faces of the thread engaging portion 36 are at an acute angle to each other so that the thread contacts with the thread engaging element in a limited region at the point 37. As the looper moves on into the needle thread loop the needle thread loop will be gradually given up to the looper giving it plenty of slack to move to the end of its stroke without unduly straining the looper thread.

It is thought that the operation of the thread controller will be obvious from the detailed description which has been given above. The essential features of the thread. controller reside in the shaping of the thread engaging portions to gradually take up the hread under positive control as the looper starts on its retracting movement; the means for stripping the thread from the thread engaging faces as to give ample slack to the looper; the control of the thread as the looper is moving to the rear end of its stroke; the taking up of the thread as the looper moves forward so as to prevent the buckling of the thread in front of the eye of the looper, which controlling of the thread is accomplished by the second thread engaging portion of the controlling element, and the final giving up of thread at is moves to the forward end of its stroke. The thread controller as a whole during the cycle of movement of the looper performs these functions which results in a very efficient control of the thread at all times during the stitch formation.

.Vhile the thread controller has been described in detail in connection with the concure by Letters Patent, is

trol of the looper thread it will be understood that it can be used for other purposes where it is de ired to take up and give up thread during stitch formation. l -Jhile it has also been shown for taking up and giving up thread twice for each cycle of operation, it will be understood that certain features of the thread controller may be used without others, as these thread taking up and giving up members operate in succession and independently of each other in their control on the thread.

it is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus fully described our invention, what we claim as new and desire to se- 1. A thread controlling mechanism for sewing machines including a rotatable thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angles to its axis of rotation, said thread controlling element having a radially projecting portion adapted to engage and take up said thread, said thread engaging portion being provided with a slot parallel to and at one side of the path of movement of the thread, and a stripper member carried by said element for stripping the thread off from said thread engaging portion into said slot, said thread engaging portion in advance of said stripper member being curved so as to gradually and positively take up the thread as the looper is retracted for holding the looper thread substantially taut until the needle point has passed the looper thread.

2. A thread controlling mechanism for sewing machines including a rotatable thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angles to its axis of rotation, said thread controlling element having a radially projecting portion adapted to engage and take up said thread, said thread engaging portion being provided with a slot parallel to and at one side of the path of movement of the thread, and a stripper member carried by said element for stripping the thread off from said thread engaging portion into said slot, said thread controlling element having a recess in which the shank portion of said stripper member is housed.

3. A thread controlling mechanism for sewing machines including a rotatable thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angle to its axis of rotation, said thread controlling element having a radially projecting portion adapted to engage and take up said thread, said thread engaging portion being provided with a slot parallel to and at one side of the path of movement of the thread, and a stripper member carried by said element for stripping the thread off from said thread engaging portion into said slot, said thread controlling element having a recess in which the shank portion of said stripper member is housed, and means whereby said stripper member may be adjusted.

at. A thread controlling mechanism for sewing machines including a rotatable thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angles to its axis of rotation, said thread controlling element having a radially projecting portion adapted to engage and take up said thread, said thread engaging portion being provided with a slot parallel to and at one side of the path of movement of the thread, and a stripper member carried by said element for stripping the thread off from said thread engaging portion into said slot, said thread engaging portion being curved in advance of said stripper member so as to gradually and positively take up the thread as the looper is retracted for holding the looper thread substantially taut until the needle point has passed the looper thread, said thread controlling element having a recess in which the shank of said stripper member is housed.

5. A thread controlling mechanism for sewing machines including a rotatable thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angles to its axis of rotation, said thread controlling element having a radially projecting portion adapted to engage and take up said thread, said thread engaging portion being provided with a slot parallel to and at one side of the path of movement of the thread, and a stripper member carried by said element for stripping the thread oif from said thread engaging portion into said slot, said thread controlling element having a recess in which the shank portion of said stripper member is housed, said thread controlling element having a second thread engaging portion for taking up and giving up thread.

6. A thread controlling mechanism for sewing machines including a rotatable thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angles to its axis of rotation, said thread controlling element having a radially projecting portion adapted to engage and take up said thread, said thread engaging portion being provided with a slot parallel to and at one side of the path of movement of the thread, and a stripper member carried by said element for stripping the thread off from said thread engaging portion into said slot, said thread controlling element having a second radially projecting thread engaging portion adapted to engage and take up said thread, the faces of said thread controlling element adjacent said second thread engaging portion being inclined at an acute angle to each other so as to provide a limited thread controlling surface.

7. The combination of a. thread carrying looper, means for oscillating said thread carrying looper, a thread controlling mechanism for the looper thread including a rotating thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angles to its axis of rotation, said thread controlling element having a radially projecting portion, the thread engaging face of which is .of gradually increasing radius,

8. The combination of a thread carrying i looper, means for oscillating said thread carrying looper, a thread controlling mechanism for the looper thread including a rotating thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angles to its axis of rotation, said thread controllingelement having a'radially projecting portion, the thread engaging face of which is of gradually increasing radius, Y said thread engaging element being timed so as to take up the looper thread on the retracting movement of the looper and hold said thread substantially taut until the needle point has passed the looper thread, said thread controlling element having means for giving up slack to the looper thread quickly when the point of the needle has passed the looper thread, said last-named means comprising a slot in the thread engaging face of the thread controlling element, and a stripper member for stripping the thread from the thread engaging face into said slot.

9. The combination of a thread carrying looper, means for oscillating said thread carrying looper, a thread controlling mechanism for the looper thread including a rotating thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angles to its axis of rotation, said thread controlling element having a radially projecting portion, the thread engaging face of which is of gradually increasing radius, said thread engaging element being timed so as to take up the looper thread on the retracting movement of the looper and hold said thread substantially taut until the needle point has passed the looper thread, said thread controlling element having means for giving up slack to the looper thread quickly when the point of the needle has passed the looper thread, said last-named means comprising aslot in the thread engaging face of the thread controlling element,

and a stripper member for stripping the" thread from the thread engaging face into said slot, said slot being so proportioned as to provide a thread engaging shoulder therein for the looper thread which gradually gives up the looper thread to the looper as it moves to the rear end of its stroke.

10. The combination of a thread carrying looper, means for oscillating said thread carrying looper, a thread controlling mechanism for the looper thread including a rotat- I ing thread controlling element, thread guides associated therewith for directing a thread into engagement with said element in a direction at right angles to its axis of rotation, said thread controlling element having a radially projecting portion, the thread engag ing face of which is of gradually increasing radius, said thread engaging element being tures.

timed so as to take up the looper thread on the retracting movement of the looper and hold said thread substantially taut until the needle point has passed the looper thread, said thread controlling element having means for giving up slack to the looper thread quickly when the point of the needle has passed the looper thread, said last-named means comprising a slot in the thread engaging face of the thread controlling element, and a stripper member for stripping the thread from the thread engaging face into said slot, said slot being so proportioned as to provide a thread engaging shoulder therein for the looper thread which gradually gives up the looper thread to the loo er as it moves to the rear end of its stro (e, said thread controlling element having means for taking up the looper thread as the looper moves forward until the point of the looper is well into the needle thread loop and for giving the thread to the looper as it moves tothe end of its stroke.

In testimony whereof, We aflix our signa- FREDERICK F. ZEIER. CHARLES F. RUBEL. 

